Kernel timers infrastructure

["Marc Lörner"]

Hello again,
it seems that uprintf needs a tty to put output to.
I tried your code with printf instead of uprintf and got
output to root-console ttyu0 every second.

HTH,
Marc

-------- Original-Nachricht --------
> Datum: Mon, 12 Sep 2011 11:58:37 +0200
> Von: Filippo Sironi <filippo.sironi at gmail.com>
> An: "Marc Lörner" <loerner at gmx.de>
> CC: freebsd-hackers at freebsd.org
> Betreff: Re: Kernel timers infrastructure

> This is how I modified the module:
> --------------------------------------------------------------------------------
> #include <sys/param.h>
> #include <sys/kernel.h>
> #include <sys/module.h>
> #include <sys/systm.h>
> 
> static struct callout timer_callout;
> 
> static void
> timer_function(void *arg)
> {
> 	uprintf("timer_function() begin\n");
> 	if (callout_reset(&timer_callout, hz, timer_function, NULL))
> 		uprintf("callout_reset() != 0\n");
> 	uprintf("Hello, World!\n");
> 	uprintf("timer_function() end\n");
> }
> 
> static int
> timer_event_handler(struct module *mod, int cmd, void *arg)
> {
> 	uprintf("timer_event_handler() begin\n");
> 	switch (cmd) {
> 	case MOD_LOAD:
> 		uprintf("MOD_LOAD\n");
> 		callout_init(&timer_callout, CALLOUT_MPSAFE);
> 		if (callout_reset(&timer_callout, hz, timer_function, NULL))
> 			uprintf("callout_reset() != 0\n");
> 		break;
> 	case MOD_UNLOAD:
> 		uprintf("MOD_UNLOAD\n");
> 		callout_drain(&timer_callout);
> 		break;
> 	case MOD_SHUTDOWN:
> 		uprintf("MOD_SHUTDOWN\n");
> 		break;
> 	default:
> 		return EOPNOTSUPP;
> 	}
> 	uprintf("timer_event_handler() end\n");
> 	return 0;
> }
> 
> static struct moduledata timer_moduledata = {
> 	"timer",
> 	timer_event_handler,
> 	NULL
> };
> 
> DECLARE_MODULE(timer, timer_moduledata, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
> --------------------------------------------------------------------------------
> and this is the output of load and unload operations:
> freebsd# kldload ./timer.ko
> timer_event_handler() begin
> MOD_LOAD
> timer_event_handler() end
> freebsd# kldunload timer.ko
> timer_event_handler() begin
> timer_event_handler() begin
> MOD_UNLOAD
> timer_event_handler() end
> 
> I don't know why "timer_event_handler() begin" is printed twice on unload
> but the timer doesn't start... and of course it is set on 1 second but I
> left the module load for 1 minute or so just to be sure. ;)
> 
> Thanks again for your help,
> Filippo
> 
> On 12/set/2011, at 11:48, Marc Lörner wrote:
> 
> > Hello,
> > what about changing order of callout_reset and uprintf?
> > And your timeout isn't 1minute, it's one second!
> > 
> > Regards,
> > Marc
> > -- 
> > Empfehlen Sie GMX DSL Ihren Freunden und Bekannten und wir
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> 

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